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From: Wolfram Sang <wsa@kernel.org>
To: Marek Vasut <marex@denx.de>
Cc: linux-i2c@vger.kernel.org, Michal Simek <michal.simek@xilinx.com>,
	Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Subject: Re: [PATCH v2 0/6] i2c: xiic: Fix broken locking
Date: Tue, 14 Sep 2021 12:29:36 +0200	[thread overview]
Message-ID: <YUB5kIM3CtuOIPeq@ninjato> (raw)
In-Reply-To: <20210823214145.295104-1-marex@denx.de>

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On Mon, Aug 23, 2021 at 11:41:39PM +0200, Marek Vasut wrote:
> Booting ZynqMP with XIIC I2C driver shows multitude of race conditions
> in the XIIC driver. This is because locking is completely missing from
> the driver, and there are odd corner cases where the hardware behaves
> strangely.
> 
> Most of these races could be triggered easily when booting on SMP
> machines, like the ZynqMP which has up to 4 cores. It is sufficient
> for the interrupt handler to run on another core than xiic_start_xfer
> and the driver fails completely.
> 
> This does not add support for long transfers, this only fixes the
> driver to be usable at all instead of being completely broken.
> 
> The V2 fixes a few remaining details which cropped up in deployment
> over the last year or so, so I believe the result should be reasonably
> well tested.
> 
> Marek Vasut (6):
>   i2c: xiic: Fix broken locking on tx_msg
>   i2c: xiic: Drop broken interrupt handler
>   i2c: xiic: Defer xiic_wakeup() and __xiic_start_xfer() in
>     xiic_process()
>   i2c: xiic: Switch from waitqueue to completion
>   i2c: xiic: Only ever transfer single message
>   i2c: xiic: Fix RX IRQ busy check
> 

Applied to for-next, thanks everyone!


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  parent reply	other threads:[~2021-09-14 10:29 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-23 21:41 [PATCH v2 0/6] i2c: xiic: Fix broken locking Marek Vasut
2021-08-23 21:41 ` [PATCH v2 1/6] i2c: xiic: Fix broken locking on tx_msg Marek Vasut
2021-08-23 21:41 ` [PATCH v2 2/6] i2c: xiic: Drop broken interrupt handler Marek Vasut
2021-08-23 21:41 ` [PATCH v2 3/6] i2c: xiic: Defer xiic_wakeup() and __xiic_start_xfer() in xiic_process() Marek Vasut
2021-08-23 21:41 ` [PATCH v2 4/6] i2c: xiic: Switch from waitqueue to completion Marek Vasut
2021-08-23 21:41 ` [PATCH v2 5/6] i2c: xiic: Only ever transfer single message Marek Vasut
2021-08-23 21:41 ` [PATCH v2 6/6] i2c: xiic: Fix RX IRQ busy check Marek Vasut
2021-08-24  6:58 ` [PATCH v2 0/6] i2c: xiic: Fix broken locking Michal Simek
2021-08-27  8:31   ` Raviteja Narayanam
2021-08-27  8:34     ` Michal Simek
2021-09-14 10:29 ` Wolfram Sang [this message]
2021-09-14 11:54   ` Michal Simek

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